Architect has not delivered - who will bear the costs?

Show me the self-designed example that you wanted to prepare for your architect last time. You received so much information back then that your design should reflect this both in terms of QM and the layout design. You can't just say we have €450k but want this and that. You can also build a complex house on a slope, say we'll take the fireplace, KNX, make the photovoltaic system smaller, or reduce by 10 sqm, you won't get it much cheaper. That doesn't work, especially if these things were not in the budget beforehand.

..and here I agree with you, the architect should have told you directly in the first meeting that what is desired is two sizes too big.

Our point is that a construction budget was set from the beginning, which also appears in the contract.

How is the budget fixed in the contract? In the beginning, we also planned that - not a single architect went along with it. How could they, the massive additional costs often only come after service phase 4.

In the floor plan thread, I just read that this is then the second architect you are showing the door. Well, without meaning it badly: where can one still help there?

I have read through both threads again; in my opinion, the problem does not primarily lie with the architect, but with unrealistic expectations on your part. This has already been explained to you from different sides in this forum, repeatedly with new arguments. You do not want to hear it.

That the architect even starts the drawing with such ideas is an audacity. But you were also very naive to expect 450k with such an idea. 450k is a small house without a basement, without a garage, without extras. So a lot is already amiss with you as well.

Well, I can understand that his demands are too high. But some statements here, like getting only a doghouse for 450k, without a garage and, it almost sounds like, without a front door, are also unrealistic. As I said, friends are currently building. A city villa, including garage and carport, good standard, corner windows, underfloor heating, etc. for 330k + 50k additional costs. It's almost like in the car forum here, everyone belongs to the top 3% and a car with a list price <80k is just enough to go get some bread.

So I can understand that his expectations are too high. But some statements here, like for 450k you only get a dog house, without a garage and, it almost sounds like, without a front door, are also out of touch with reality.
As I said, friends are currently building. City villa, including garage and carport, good standard, corner windows, underfloor heating, etc. for 330k + 50k additional costs.
It's almost like in the car forum here, everyone belongs to the top 3% and a car with an LP <80k is barely enough to get the bread.

No one writes that. In the other thread, Jochen is building 120sqm with a basement for 330k€ without additional costs (probably without earthworks and the usual other stuff) and even there I personally think that 400k€ (all in) will not be enough or only just enough. Johann almost has 120sqm on one of 3.5 floors and finds that just enough for 3 people. Of course, you can argue about who is out of touch with reality here... or not.